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Study Objectives: Hypoglossal nerve stimulation (HGNS) has been widely used to treat obstructive sleep apnea in selected patients. Here we evaluate rates of revision and explant related to HGNS implantation and assess types of adverse events contributing to revision and explant., Methods: Postmarket surveillance data for HGNS implanted between January 1, 2018 and March 31, 2022, were collected. Event rates and risk were calculated using the postmarket surveillance event counts and sales volume over the same period. Indications were categorized for analysis. Descriptive statistics were reported and freedom from explant or revision curves were grouped by year of implantation., Results: Of the 20,881 HGNS implants assessed, rates of explant and revision within the first year were 0.723% and 1.542%, respectively. The most common indication for explant was infection (0.378%) and for revision was surgical correction (0.680%). Of the 5,820 devices with 3-year postimplantation data, the rate of explant was 2.680% and of revision was 3.557%. During this same interval, elective removal (1.478%) was the most common indication, and for revisions, surgical correction (1.134%)., Conclusions: The efficacy of HGNS is comparable in the real world setting to published clinical trial data. Rates of explant and revision are low, supporting a satisfactory safety profile for this technology., Citation: Moroco AE, Wei Z, Byrd I, et al. Device-related outcomes following hypoglossal nerve stimulator implantation. J Clin Sleep Med . 2024;20(9):1497-1503., (© 2024 American Academy of Sleep Medicine.)

Background: Irreversible electroporation (IRE) is a nonthermal ablation modality. A 200-J application can create deep myocardial lesions, but gas bubbles are created at the ablation electrode. Cerebral effects of these bubbles are unknown., Objective: The purpose of this study was to investigate gas microemboli-induced brain lesions after IRE and radiofrequency (RF) ablation to the left side of the canine heart, using magnetic resonance imaging (MRI) and histopathology., Methods: In 11 canines, baseline cerebral MRI scans were performed. In 9 animals, after retrograde femoral artery access, 12 ± 4 200-J IRE applications were administered in the ascending aorta. In 2 animals, 30 minutes of irrigated 30-W RF ablation using 10-30g of contact force was applied in the left ventricle. At days 1 and 5 after ablation, MRI was repeated. The brain tissue then was histopathologically examined., Results: All ablations and follow-up were uneventful. Intracardiac echography confirmed gas bubble formation after each IRE application. Neurologic examination was normal. MRI scans were normal in all animals at day 1 and were normal in 10 of 11 animals at day 5. In 1 animal, a single <2-mm-diameter lesion in the right temporal region could not be excluded as a small infarct or early hemorrhagic site. Histopathologic analysis of the same region showed no pathologic changes. In all other animals, gross and microscopic pathology were normal., Conclusion: MRI images alone or in combination with histologic follow-up did not reveal treatment-related embolic events. Gross and microscopic pathology did not reveal evidence of treatment-related embolic events. IRE seems to be a safe ablation modality for the brain., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Titanium dioxide nanofiber (TDNF) is widely used in the manufacture of various household products, including cosmetics. As a result, the possibility exists for TDNFs to affect human health. Because the kidneys are responsible for filtering out waste from the blood, the goal of the present study was to investigate the short-term effects of TDNF on kidney function of male Sprague Dawley rats. To achieve study objectives, 6- to 7-wk-old male rats were exposed via oral gavage to a total of 0, 40, and 60 parts per million of TDNF for 2 wk. The TDNF was fabricated by electrospinning and then dissolved in water. We measured serum concentration of lactate dehydrogenase, renal histopathology, identification of TDNF in kidney tissue via scanning electron microscopy, and quantitative amounts of titanium-47 in kidney tissue. We also measured specific gene-expression analysis of transcripts involved in apoptosis, inflammation, cell-division regulation, cell structure, and motility. Results showed a slight dose-dependent reduction in renal weight. In contrast, a concentration-dependent elevation in titanium-47 amounts was noted in kidney tissue. We found no significant differences in histopathological patterns. Gnat3 and Hepacam3 were up-regulated in TDNF-treated groups. Up-regulation of NF-κB likely indicated the involvement of renal-tissue inflammation via an independent mechanism. Similarly, Gadd45-α was significantly overexpressed in kidney tissues. This transcript was previously increased following stressful growth-arrest conditions and treatment with DNA-damaging agents. Our overall results suggest marginal renal toxicity in Sprague Dawley rats after ingesting TDNF.

Alloy electrode material like tin dioxide (SnO2) possesses much higher specific capacity as compared to commercial graphite anode in lithium ion battery (783 vs 372 mAh g(-1)). However, the huge volume change (260%) of SnO2-based anode during the alloying and dealloying process can cause significant electrode pulverization and rapid capacity loss. Herein we report the synthesis of SnO2 asymmetric membranes via a unique combination of phase inversion and sol-gel chemistry to overcome this big challenge. The SnO2 asymmetric membrane electrode demonstrates a specific capacity of 500 mAh g(-1) based on the overall electrode mass at a current density of 280 mA g(-1) (∼0.5C) with >96% capacity retention after 400 cycles. When the current density is increased from 28 to 560 mA g(-1), its overall capacity is only reduced by 36%. Such an outstanding rate and cycling performance is attributed to the existence of networking porous structure in the membrane that can provide high electrical conductivity, multiple diffusion channels, and free volumes for electrode expansion. The carbonization temperature has a dramatic impact on the electrode performance. Membranes carbonized at 500 °C show an excellent cycling performance, whereas the capacity of the membrane carbonized at 800 °C decreases by 51% in 100 cycles. Such a drastic difference in cycle life is caused by the reduction of small SnO2 NPs (∼3.9 nm) into large metallic tin spheres (∼40 nm) at 800 °C. This is the first original report on using asymmetric membrane structure to stabilize an SnO2-based lithium ion battery anode with an excellent electrochemical performance.

Purpose: Voltage-based device-tracking (VDT) systems are commonly used for tracking invasive devices in electrophysiological cardiac-arrhythmia therapy. During electrophysiological procedures, electro-anatomic mapping workstations provide guidance by integrating VDT location and intracardiac electrocardiogram information with X-ray, computerized tomography, ultrasound, and MR images. MR assists navigation, mapping, and radiofrequency ablation. Multimodality interventions require multiple patient transfers between an MRI and the X-ray/ultrasound electrophysiological suite, increasing the likelihood of patient-motion and image misregistration. An MRI-compatible VDT system may increase efficiency, as there is currently no single method to track devices both inside and outside the MRI scanner., Methods: An MRI-compatible VDT system was constructed by modifying a commercial system. Hardware was added to reduce MRI gradient-ramp and radiofrequency unblanking pulse interference. VDT patches and cables were modified to reduce heating. Five swine cardiac VDT electro-anatomic mapping interventions were performed, navigating inside and thereafter outside the MRI., Results: Three-catheter VDT interventions were performed at >12 frames per second both inside and outside the MRI scanner with <3 mm error. Catheters were followed on VDT- and MRI-derived maps. Simultaneous VDT and imaging was possible in repetition time >32 ms sequences with <0.5 mm errors, and <5% MRI signal-to-noise ratio (SNR) loss. At shorter repetition times, only intracardiac electrocardiogram was reliable. Radiofrequency heating was <1.5°C., Conclusion: An MRI-compatible VDT system is feasible., (Copyright © 2013 Wiley Periodicals, Inc.)

Convention holds that the magnitude of an electrogram (EGM) recorded from an ablation catheter indicates proximity to the tissue and may be used to guide tip placement. The shift in capacitance (phase angle) as the electrode touches the tissue may be a better guide. We compared these two methods over a range of distances in close proximity to heart tissue. This study suggests that EGM is not a reliable predictor of proximity to tissue within a few millimeters of the surface. Thus, EGM alone should not be used to guide electrode placement for ablation, as a millimeter off the surface will shift a greater percentage of delivered energy to the blood pool rather than the target tissue. EGM should also not be used to gauge force of the catheter into tissue. Phase angle is a better predictor of both variables, but an optimal combination of predictors remains to be found.